Avaliação da fotoatividade de revestimentos de TIO2 em substrato cimentício

Abstract

Cementitious materials are continuously exposed to a variety of atmospheric pollutants, microorganisms and to different weather conditions causing changes in the properties of these materials. Repair and restoration works are being done to prevent and control such changes, although the problem isn’t completely eliminated due to the effect of atmospheric pollutants and microorganisms still unknown from cementitious materials. To solve such problems, researches have been using coating to improve some of the cement-based materials’ properties. The objective of this work was to develop a titanium dioxide coating that after exposed to UV radiation, starts to have self-cleaning properties and helps the air purification. However, its application in cementitious materials still presents some technological difficulties, given that the imperfections and superficial porosity of these materials hinder the deposition of a uniform layer. The aim of this present work was to develop a titanium dioxide coating, with the crystalline form anatase, and cementitious substrates were coated. When exposed to UV radiation, this material starts to present properties like self-cleaning, photocatalytic, and helps the air purification. Static water contact angle and RhB degradation were used to assess the photo-induced activity of the films. It was noticed an increase in the rate of degradation of RhB and a decrease on static water contact angle when exposed to UV radiation. All the substrates exhibit a significant increasement in photoactivity after UV exposition. The results suggest that the pastes with addition did not present any significant differences in coating behavior.